Indications and effectiveness of technique for immature oocyte-cumulus complexes retrieval from ovarian tissue followed by their in vitro maturation

Objective: To develop tactics for preserving genetic material in patients with malignant ovarian neoplasms using the technique for immature oocyte retrieval from ovarian tissue, ovarian tissue oocyte in vitro maturation (OTO IVM) and cryopreservation; to identify the indications and limitations of OTO IVM. Materials and methods: Seventy-two patients diagnosed with ovarian cancer or borderline ovarian tumors were examined prior to surgical treatment. The patients were evaluated for clinical and anamnestic characteristics, reproductive function and ovarian reserve, and characteristics of the oncological process; risk factors that could influence OTO IVM outcome were determined as well. Each patient underwent retrieval of oocyte-cumulus complexes (OCC) from one or two ovaries, followed by their identification and in vitro maturation. Depending on the patient’s desire, the obtained oocytes were cryopreserved or fertilized with biological material of the partner. Results: The patients were divided into two groups depending on the outcome of the OTO IVM program. Group 1 consisted of 17 patients who had a successful outcome of the program, namely, at least five mature oocytes and/ or one or more embryos were preserved. Group 2 included 55 patients with an unsuccessful outcome. The main factors that could influence OTO IVM outcome were identified. Conclusion: It was possible to determine the criteria for the selection of patients for using the OTO IVM technique. The results of the study showed that the use of OTO IVM can provide a sufficient number of OCC in young patients in case of good indicators of ovarian reserve, no preliminary resection of the ovaries, and if sufficient amount of ovarian tissue not affected by tumor was sent to the laboratory of embryology. This technique continues to be experimental: in spite of successful retrieval of OCC and oocyte in vitro maturation, high-quality blastocysts are cultivated less frequently than in assisted reproductive technologies and this may affect negatively the result of the treatment, namely, establishing pregnancy in this cohort of patients

in vitro maturation, IVM, ovarian tissue IVM, OTO IVM, oncofertility, in vitro maturation, IVM, ovarian tissue IVM, OTO IVM, fertility /reservation, ovarian cancer, ovariectomy, borderline ovarian tumors